Woodworking often involves cutting or shaping pieces of wood in close proximity to high-speed saw blades, cutters or moving abrasives. These devices present a substantial risk to the hands and fingers of the tool operator, particularly when the work piece is small or the piece to be removed is small or thin. To reduce the risk of working so close to such dangerous machinery, a variety of pushing and guiding systems have been developed for use with cutting and abrasive tools.
U.S. Pat. No. 6,591,724, issued to Huang, discloses an improved structure for saw clip. On the working deck, there is a lead trough. On the pivot of this working deck, there is a block section for items to wait to be sawed. A top pusher block, when moved onwards, can be used to fix the items so that the sawing process can go smoothly. Among the parts of this invention, there is a sliding trough on top of the block and the sliding trough and the lead trough go across each other. Moreover, a lead screw goes through both the sliding trough and lead trough. The lead screw can be adjusted to be at any position in the lead trough to change how the block is placed. Then, the block can be screwed tightly so that it will not turn upon receiving the pushing force from clipping.
U.S. Pat. No. 6,578,461, issued to Loo, describes a combination rip fence and work piece pusher that is provided for a table saw or shaper. A preferred work piece pusher moves along a track having a central portion aligned with the feed direction and having two end portions skewed with respect to the feed direction so that the work piece pusher retracts into the rip fence at both limits of its travel. This allows a sawyer to retract the work piece pusher on the infeed side of a table saw and begin a ripping operation in which he or she manually pushes the work piece into the saw blade until the trailing end of the work piece is close enough to the saw blade that the work piece pusher can be moved out of the fence to engage the trailing end of the stock. The pusher can then be used to push the work piece the rest of the way past the blade. This apparatus also allows a woodworker to operate a table-mounted cutting tool without using a work piece pusher of the invention that is installed on that table. In this mode of operation, if the work piece pusher is incidentally engaged by the work piece, the work piece pusher does not jam the work piece into the tool or into the rip fence, but is merely pushed to the outfeed side of the table where it retracts within the rip fence.
U.S. Pat. No. 6,732,623, issued to Jennings, illustrates a safety push tool for use with table mounted cutting tools. The push tool is of the type having a carrier guide body with an underside adapted to rest on a work piece to be moved along a cutting tool. The safety push tool has a handle portion and the improvement of the present invention is the construction of the back heel member which is held at the slot of the back of the tool. The back heel member is a U-shaped device which fits over a slot over the back of the tool. The back heel member is a U-shaped device which fits over a support arm and can be rotated from a first position where two separate arms depend downwardly from the underside. It also can be moved in a second position where a cross member headstock extends below the underside of the safety push tool.
U.S. Pat. No. 5,894,777, issued to Sterling, discloses a protective push stick that includes a transparent cover extending over the cutting tool of a machine tool to protect the operator's hand from the saw blade, to protect the operator's eye from particles flying upwards from the cutting tool and still provide some visibility of the cutting tool to the operator.
U.S. Pat. No. 5,678,467, issued to Aigner, describes an exchangeable handle for wooden pushers which handle includes a grip having a base plate which is L-shaped in cross section, this base plate having a long leg and a short leg in which spikes are provided for driving into the wooden pusher. The spikes attached to the short leg project at right angles from the short leg and extend parallel to the long leg. The spikes provided at the free end of the long leg are attached to a swivel lever which is rotatable about a shaft. The spikes which project out of the long leg through openings therein can be swiveled by an actuating lever from a direction substantially parallel to the sort leg into an engagement position at an angle thereto.
U.S. Pat. No. 6,135,521, issued to Wirth, Jr., et al., shows a push stick for use with woodworking equipment is provided with a main body having two stepped portions or notches for positive engagement with a work piece. The push stick has an ergonomically designed, open grip handle and non-slip pads on working surfaces for control and ease of use.
U.S. Pat. No. 5,148,846, issued to Van Gelder, describes a work piece guide to help feed boards into a woodworking machine such as a power saw. The guide is adapted to hold the board against the guide fence as the board is fed into the saw by pressing a knurled wheel down against the board. The wheel is slightly angled to move the board toward the fence and is pressed down against the board by a leaf spring thus keeping the board from riding up on the blade.
U.S. Pat. No. 6,044,740, issued to Werkheiser, discloses a push stick for use with stationary power tools including table saws and shapers. The push stick has a flat base plate that can ride on the surface of the power tool thereby providing stable operation with a resulting increase in safety for the operator and more accurate cutting. A handle of the push stick is placed at an optimum angle to provide both downward and forward pressure on a work piece. The push stick may also be equipped with a variable handle angle to optimize its use with different power tools. The base plate of the push stick may be adjustable in thickness to accommodate work pieces of different thicknesses.
U.S. Pat. No. 5,016,509, issued to Stottman, describes a combination safety guide and measuring tool providing a safe, reliable means for advancing wood over or through table mounted wood working equipment, and in addition, providing a measuring tool for many important wood working problems. Among the unique features provided by this device are a conventional push tool, a means for measuring the distance of the cutting tool from the wood piece, and a means for accurately measuring the height of the cutting instrument. Because of the unique design of this invention, the worker can perform many measuring functions without the necessity of several measuring tools and, in addition, have a safe, reliable push stick for moving the wood piece through the wood working equipment.
It is an objective of the present invention to provide a pushing device to guide and position work pieces of varying thickness into cutting or abrasive power tools in a manner that is safe and accurate. It is a further objective to provide a pushing device that can be easily grasped and controlled by one hand. It is a still further objective of the invention to provide a pushing device that can be easily used in both vertical and horizontal planes. It is yet a further objective to provide a pushing device that can be easily, inexpensively and accurately manufactured. Finally, it is an objective of the invention to provide a pushing device that can easily be used with either hand.
While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.